Manceron Audrey, Jawa Andrew, Mantovani Matteo, Werthel Jean-David
Service de Chirurgie Orthoépdique et Traumatologique, Hôpital Ambroise Paré, Boulogne-Billancourt, France.
Department of Orthopaedic Surgery, New England Baptist Hospital, Boston, MA, USA.
J Shoulder Elbow Surg. 2025 Jan 30. doi: 10.1016/j.jse.2024.12.018.
Shoulder movements result from the combined movements of the glenohumeral (GH) joint and the scapulothoracic (ST) joint, following a rhythm known as the scapulohumeral rhythm (SHR). The SHR represents the ratio of glenohumeral movement to scapulothoracic movement during arm elevation. Numerous studies have demonstrated that scapulothoracic kinematics and the SHR are significantly modified after reverse total shoulder arthroplasty (rTSA). This study aimed to analyze scapulothoracic motion post rTSA and compare it to that of an asymptomatic healthy shoulder.
Thirteen shoulders formed the rTSA group. All patients had undergone rTSA for primary osteoarthritis (9 shoulders) or cuff tear arthropathy (5 shoulders) between 2017 and 2022. The healthy group consisted of 25 adult volunteers with no previous medical or surgical history involving the shoulder or spine. Analyses were performed bilaterally. For each patient, clinical (shoulder range of motion), functional (Constant score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, and Subjective Shoulder Value), and scapular kinematic assessments were conducted using miniature inertial measurement units.
Scapular upward rotation was significantly increased in rTSA patients compared with healthy controls starting from 60° of elevation (P < .01). Scapular retraction was also significantly higher in rTSA patients compared with healthy controls from the beginning of elevation (P < .01). No significant difference in scapular tilt was found between rTSA and healthy patients. The SHR of healthy controls varies during abduction, from 7 at 30° to 4 at the end of the movement, indicating increased involvement of the ST joint relative to the GH joint. In contrast, the SHR in the rTSA cohort remains stable throughout abduction, from 2.4 at the beginning to 2.8 at the end, suggesting a greater contribution of the ST joint to abduction in rTSA patients than in the healthy controls, especially at the movement's initiation.
This study demonstrates that the kinematics of the ST joint during overhead motion after a well-functioning rTSA are significantly altered compared with a healthy shoulder. Overhead motion was associated with a significant increase in scapular external rotation and retraction in rTSA patients, with no difference in scapular tilt. The ST contribution to overall shoulder movement is significantly increased in patients with an rTSA compared with a healthy shoulder. Better understanding of ST motion after rTSA could help improve rehabilitation protocols and preoperative planning for rTSA.
肩部运动是由肱盂（GH）关节和肩胛胸壁（ST）关节的联合运动产生的，遵循一种称为肩胛肱骨节律（SHR）的节奏。SHR代表手臂抬高过程中肱盂运动与肩胛胸壁运动的比例。大量研究表明，全肩关节置换术（rTSA）后肩胛胸壁的运动学和SHR会发生显著改变。本研究旨在分析rTSA术后肩胛胸壁的运动，并将其与无症状健康肩部的运动进行比较。
13个肩部组成rTSA组。所有患者在2017年至2022年期间因原发性骨关节炎（9个肩部）或肩袖撕裂性关节病（5个肩部）接受了rTSA手术。健康组由25名成年志愿者组成，他们既往没有涉及肩部或脊柱的医疗或手术史。分析是双侧进行的。对每位患者进行临床（肩部活动范围）、功能（Constant评分、美国肩肘外科医师协会标准化肩部评估表和主观肩部评分）以及使用微型惯性测量单元进行肩胛运动学评估。
与健康对照组相比，rTSA患者从抬高60°开始，肩胛上旋明显增加（P <.01）。与健康对照组相比，rTSA患者从抬高开始时肩胛后缩也明显更高（P <.01）。rTSA患者与健康患者之间在肩胛倾斜方面未发现显著差异。健康对照组的SHR在外展过程中有所变化，从30°时的7到运动结束时的4，表明相对于GH关节，ST关节的参与度增加。相比之下，rTSA队列中的SHR在整个外展过程中保持稳定，从开始时的2.4到结束时的2.8，这表明rTSA患者中ST关节对外展的贡献比健康对照组更大，尤其是在运动开始时。
本研究表明，与健康肩部相比，功能良好的rTSA术后头顶运动期间ST关节的运动学发生了显著改变。头顶运动与rTSA患者肩胛外旋和后缩的显著增加相关，肩胛倾斜无差异。与健康肩部相比，rTSA患者中ST关节对整体肩部运动的贡献显著增加。更好地了解rTSA术后的ST运动有助于改进rTSA的康复方案和术前规划。
